Method of making sliders



Aug. 18, 1936. G. DAHLlN 2,051,548

METHOD OF MAKING SLIDERS Filed July 27, 1935 VENTO I I Ys.

UNITED STATES PATENT OFFICE METHOD or MAKING sLmERs Gustaf Dahlin, St. Catharines, Ontario, Canada,

assignor to Hookless Fastener Company, Meadville, Pa., a corporation of Pennsylvania Application July 27, 1933, Serial No. 682,477

1 Claim.

This invention relates to separable interlocking fasteners of the type having a series of fastener members which are engaged and disengaged by movement'of a slider along the rows of fastening members. i

The invention is particularly concerned with an improved slider and an improved method of making the same.

Sliders for separable slide fasteners have been made from metal and in order to keep the cost down to a minimum, the slider is built up from sheet metal blanks in various ways or the slider is pressed and bent to the desired shape from strip metal.

separable interlocking fasteners have been made from non-metallic materials, including, for example, the cellulosio products such as pyralin and phenolic condensation products, such as bakelite.

It is desirable to make the sliders for such fasteners of the same material.

While it might be possible to mold such sliders to form it is believed that that method would have seri- OllS disadvantages in actual production. It

would require expensive equipment and would be difficult to control in production.

According to the present invention, a slider is provided which has all the requisites of a good slider, possessing the maximum stiffness and strength and the most compact and pleasing appearance possible.

Since it is difiicult to bend and shape nonmetallic materials of the character mentioned, my invention has for its principal object to provide a method of making sliders which will avoid all bending and forming operations. More particularly, according to the invention, a slider body is formed solely by cutting material from a solid block.

In the accompanying drawing I have shown for purposes of illustration, one embodiment which my invention may assume in practice. In the drawing:

Fig. 1 is a perspective view showing the solid blank Fig. 2 shows the blank after the first operation;

Fig. 3 shows the blank after the second operation;

Fig. 4 is a perspective view of the pull attaching lug; and

sired manner.

It corresponds in size and shape to the external contour of the finished slider except for a pull attaching loop or lug. The blank is of generally keystone shape with a narrow end designated 6, and a wide end designated 1. The outer corners are preferably bev- 5 eled off as indicated at 8 and the corners along the sides are rounded as appears at 9. In the first operation, slots ID are cut through the sides of the blank by milling cutters or saws, such slots being of the same width as the side 10 slots in the finished slider. It will be understood that certain non-metallic materials, such as those here under consideration, of which cellulose nitrate may be considered a good example, may be cut rapidly by tools shaped similar to wood-cutting tools. Sawing or milling operations therefore can be carried out at high speed and at a minimum of expense.

The second operation, the result of which appears in Fig. 3, may be termed a breaching oper- 90 ation. It is preferably done with a circular tool d having teeth along its circumference and cutting edges extending radially along the side faces. The teeth are of just sufiicient length to leave lateral flanges ll of the desired thickness. This milling operatic-n provides a Y-shaped channel with a lower branch !2, and diverging upper branches l3. Between the diverging branches there is left a V or wedge-shaped neck M which is integrally connected with the upper and lower wings I5, I6 respectively.

In order to complete the slider it is necessary to stick in place a loop or lug H, which connects a pull tab I8 to the slider. If the parts are made of cellulose nitrate or other soluble material, the piece I! may be stuck in place by softening its ends in solvent and pressing them in contact with the slider.

As a result of my invention, it will be observed that a compact slider of the most advan- 4Q tageous design can be produced by simple operations at relatively low cost. All bending and forming operations are avoided so that the sliders can be easily made from non-metallic materials of the character mentioned.

While I have in this application specifically shown and described one embodiment which my invention may assume in practice, it will be understood that this embodiment is merely for the purposes of illustration and description and that various other forms may be devised within the scope of my invention as defined in the following claim.

What I claim as my invention is:

The method of making separable fastener sliders of the' type comprising overlying wings joined at one end by a wedge-shaped neck and having inturned flanges at the sides providing an interior Y-shaped channel opening through narrow slots at the sides between said flanges, which consists of preparing a solid block of nonmetallic material of approximately keystoneshape corresponding in size and shape to the external dimensions of the slider, milling out a 10 slot at each side of the slider the same width as the narrow slot between the flanges, said slots extending substantially all the way to the wedge-shaped neck, and then milling out material from the interior wing surfaces to enlarge the channels interiorly of the slider without enlarging the slots at the sides, all portions of the finished slider occupying the same positions as they did in the original blank.

GUSTAV DAHLIN. 1o 

